Roller skate



FIG. 1 is a front elevational view of a roller skate showing our new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a cross-sectional view thereof taken along line 3--3 of FIG. 4; and,

FIG. 4 is a side elevational view thereof. 

The ornamental design for a roller skate, as shown and described. 